The density of Herpesvirus saimiri (HVS), DNA ranges from 1.694 g/c to 1.727 g/c chloride. The HVS growth curves at high MOI (5) in owl monkey kidney cells are 48-72 hrs and 165-185 hrs at low MOI (0.01). The major HVS DNA species (1.694 and 1.704 g/c vary in yield according to the MOI. Thus at high MOI the 1.694 g/c peak is the major HVS DNA species indicating a correlation between the length of time for HVS growth and the g/c content of the viral DNA.